Diaziridinium Ions: First Reported Synthesis and Reactivity Studies. Tropylium Ion Mediated alpha-Cyanation of Amines. Multicatalytic Synthesis of Complex Tetrahydrofurans

The first synthesis and full characterization of a new functionality, called the diaziridinium ion, is reported. The original synthetic intent behind its design was to explore its potential use as a non-metal based N-transfer reagent. During this study, we have uncovered a practical rearrangement to access 2,3-benzodiazepines reliably and efficiently. Efforts to achieve N-transfer from these species are described and are ongoing.;We have identified the tropylium ion as a highly efficient organic-based amine oxidant and have demonstrated its practical use in a one-pot protocol for alpha-aminonitrile synthesis. We also report an application of this new oxidant towards an aza-Cope rearrangement.;Finally, we report a multicatalytic method that uses bismuth(III) triflate to catalyze a nucleophilic addition to an aldehyde followed by hydroalkoxylation to generate highly functionalized tetrahydrofuran rings, a motif that is often encountered in natural product architectures.